Dispensing syringes and syringe-like devices may be used for storing, mixing, transporting, and dispensing a wide variety of liquids. These devices come in many forms and configurations, including assemblies comprising a barrel having a fluid discharge end, a plunger disposed within said barrel and having a threaded rod extending therefrom for engaging the plunger for advancement relative to the barrel, and a control portion for engaging said threaded rod.
One example of the aforementioned type of dispenser is illustrated in Bergman, U.S. Pat. No. 4,144,988. The patent discloses a device with a piston and lead screw dispenser with a twistable projection. The device includes a dispenser spout at one end and is filled through the opposite end. In one embodiment, the tube and dispensing unit are made of plastic materials and the securement is by ultrasonic welding. When the dispenser tip is opened, rotating the lead screw projection will advance (determine the piston position) and discharge the tube's filling.
Likewise, U.S. Pat. No. 1,447,712 by Darley discloses a dispensing device with a screw that operates the piston via turning the operating cap. The device is filled using the nozzle in the upper shaft and operated by unscrewing the conical cap and turning the operating clockwise motion. When a sufficient quantity of paste has been ejected, the operator then reverses the direction of the operating cap, moving the piston slightly towards the bottom and preventing the paste from leaking.
The inventor herein has recognized problems with syringe-like dispensers of this kind, including issues related to their tendencies to leak, lack of portability, increased assembly complexity, and reduced ability to dispense small and accurate amounts of viscous liquids.
As one example, Bergman's plunger assembly may be prone to leakage of liquids, as compared with more paste-like fillings. Similarly, leakage from the spout during transportation and non-dispensing conditions can be significant. Further still, simple manual assembly without addition tools, such as welders, is unachievable with the described configuration. Further still, the force necessary to rotate the base and generate accurate control of the amount of dispensed liquid can be either too high or too low depending on the degree of compression required to maintain a water-tight seal between the plunger and the wall.
In one example, at least some of the above issues are addressed by a fluid dispensing device including a cylindrical housing including a dispensing tip, a movable plunger disposable in the cylindrical housing, the plunger including at least one protrusion configured to be in face-sharing contact with an inner surface of the cylindrical housing along an entirety of a dispensing path of the plunger, and a displacement element configured to at least partially extend into the dispensing tip.
In this way, the cylindrical housing forms a liquid reservoir for containing a fluid. To dispense the fluid, the plunger is advanced via a suitable actuation mechanism, such as twisting of a twistable base coupled to the plunger. In an example, the plunger includes a silicone cap to form a watertight seal with the inner surface of the housing defining the liquid reservoir. Further, the displacement element may extend and project into an interior space of the dispensing tip of the housing to create an additional flow restriction for dispensing fluid, thus enabling precise control of small liquid amounts while also reducing waste liquid retained in the device at maximum plunger displacement.
In another embodiment, the fluid dispensing device may comprise a housing body with a liquid reservoir and a slidable plunger rod with a plunger top that may be actuated into the housing body such that the plunger top acts as an displacement element and inserts into a dispensing tip of the housing body to dispense fluid from the device. A removable cap may be coupled to the housing body to plug the dispensing tip when fluid is not being dispensed.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.